A statement on Green Day's official website reads: "Billie Joe is seeking treatment for substance abuse. We would like everyone to know that our set was not cut short by Clear Channel and to apologize to those we offended at the iHeartRadio Festival in Las Vegas."

It is believed that Green Day had their set time cut from 45 minutes to just 25 in order for Usher to play for longer at the Las Vegas concert.

Reacting dramatically to being hurried along, Armstrong stopped playing his song and began speaking to the audience, saying:

"Oh, f*ck this shit. I'm gonna play a f*cking new song. F*ck this shit. Give me a f*cking break. One minute left. One minute f*cking left. You're gonna give me one f*cking minute? Look at that f*cking sign right there — one minute. Let me f*cking tell you something, let me tell you something, I've been around since f*cking 198-f*cking-8. And you're gonna give me one f*cking minute? You've gotta be f*cking kidding me! You're f*cking kidding me. What the f*ck! I'm not f*cking Justin Bieber, you motherf*ckers. You've gotta be f*cking joking. This is a f*cking joke. I got one minute — one minute left. Oh, now I got nothing left. Let me show you what one f*cking minute f*cking means. [smashes guitar] One minute. God f*cking love you all. We'll be back."

Green Day appeared at the iHeartRadio festival at the MGM in Vegas alongside Rihanna, No Doubt, Aerosmith, Lil Wayne, Pink, Taylor Swift and Usher.